The post–Cold War era is a period of history that follows the end of the Cold War, which represents history after the dissolution of the Soviet Union in December 1991. This period saw many former Soviet republics become sovereign states, as well as the introduction of market economies in Eastern Europe. This period also marked the United States becoming the world's sole superpower.
Relative to the Cold War, the period is characterized by stabilization and disarmament. Both the United States and Russia significantly reduced their nuclear stockpiles. Much of the former Eastern Bloc became democratic and was integrated into the world economy. In the first two decades of the period, NATO underwent three enlargements, and France reintegrated into the NATO command. Russia formed the Collective Security Treaty Organization to replace the dissolved Warsaw Pact, established a strategic partnership with China and several other countries, and entered the Shanghai Cooperation Organisation and BRICS alongside China, which is a rising power. Reacting to the rise of China, the United States began a gradual rebalancing of strategic forces to the Asia–Pacific region and out of Europe.